#!/usr/bin/env python3

def radicals(n):
    sieve = [1]*(n+1)
    for p in range(2,n+1):
        if sieve[p] > 1:
            continue
        for m in range(p, n+1, p):
            sieve[m] *= p
    return zip(range(n+1), sieve)

rads = list(radicals(10**5))
rads.sort(key = lambda x: x[1])
print(rads[10**4][0])